快速凝固和热压高锰硅的微观结构和热电性能  

Microstructures and thermoelectric properties of higher manganese silicide prepared by rapid solidification and hot pressing

作　　者：刘晓虎[1] 赵新兵[1] 倪华良[1] 陈海燕[1] 

机构地区：[1]浙江大学硅材料国家重点实验室,浙江杭州310027

出　　处：《功能材料与器件学报》2004年第2期231-235,共5页Journal of Functional Materials and Devices

基　　金：国家自然科学基金(No.50171064);"863计划"(No.2002AA302406)资助

摘　　要：用快速凝固和热压烧结方法制备了三种不同成分的P型高锰硅(HMS)材料MnSi_(175-x)(x=0,0.02,0.04)。微观组织结构分析表明,在Mn_4Si_7半导体相基体中,存在小区域平行分布的薄片状MnSi金属相,其形成机制是在快速凝固时的准定向凝固。随高锰硅中Si含量的增加,试样的电导率下降,Seebeck系数上升。分析表明,影响高锰硅性能的主要因素在400℃以下是载流子散射,在约500℃以上是电子激发。实验得到的热电功率因子最高值为1.3×10^(-3)Wm^(-1)K^(-1)(570℃)。Polycrystalline higher manganese silicide (HMS) with the chemical composition of MnSi_(1.75-x) (x=0, 0.02, 0.04) were prepared by rapid solidification (RS) and hot uniaxial pre.ssing (HUP). It is shown that the microstructures of the samples consist of locally parallelly distributed MnSi thin flakes in the semiconductor Mn_4Si_7 matrix due to a quasi -directional solidification during RS. It is found that electric conductivities decrease and Seebeck coefficients increase with the increase of silicon content in the material. The thermoelectric properties are controlled by carrier scattering below 400℃ and electron excitation above 500℃. The highest thermoelectric power factor obtained is 1.3×10^(-3)Wm^(-1)K^(-1) at 570℃.

关 键 词：高锰硅 快速凝固 热压 热电性能 热电材料 

分 类 号：TN304[电子电信—物理电子学]